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Is the ener­gy tran­si­tion fail­ing in many places due to water shortages?

Whether and how the glob­al­ly avail­able water favours the use of renew­able ener­gies and slows down fos­sil ener­gy sources has been inves­ti­gat­ed from dif­fer­ent per­spec­tives by nine research insti­tu­tions as well as small and medi­um-sized enter­pris­es with­in the frame­work of the joint project “Water resources as a sig­nif­i­cant fac­tor of the ener­gy tran­si­tion on a local and glob­al lev­el — WANDEL”. Among oth­er things, the project part­ners cal­cu­lat­ed the water foot­print for dif­fer­ent ener­gy sys­tems and devel­oped tools for water man­age­ment. The project, fund­ed by the Fed­er­al Min­istry of Edu­ca­tion and Research over a peri­od of three years, was joint­ly coor­di­nat­ed by the Ruhr-Uni­ver­sität Bochum (RUB) and the Uni­ver­si­ty of Kas­sel and will be com­plet­ed at the end of 2020.

It is well known that dif­fer­ent ener­gy sys­tems have dif­fer­ent water require­ments. Direct water con­sump­tion, for exam­ple for cool­ing ther­mal pow­er plants, or the reg­u­la­tion of riv­er flows for hydropow­er use, influ­ence the local water and envi­ron­men­tal sys­tems at the site of the pow­er plant. How­ev­er, the indi­rect impacts on water resources in oth­er regions of the world, for exam­ple through the min­ing of coal or cop­per, are far less well known. The WANDEL project inves­ti­gat­ed glob­al ener­gy sce­nar­ios and their impact on water resources as well as four exist­ing pow­er plant sites in three coun­tries with dif­fer­ent ener­gy sys­tems: a coal-fired pow­er plant with water cool­ing on the Weser, a chain of six run-of-riv­er pow­er plants on the Danube, a solar ther­mal pow­er plant in Moroc­co and the use of sug­ar cane bagasse to gen­er­ate elec­tric­i­ty in Brazil.

Water foot­print analy­sis for dif­fer­ent ener­gy systems

The project results show that strate­gies for trans­form­ing the ener­gy sys­tem in the con­text of the ener­gy tran­si­tion should not only take into account the reduc­tion of green­house gas emis­sions, but also water con­sump­tion. Thus, at the glob­al lev­el, sce­nar­ios with ambi­tious tar­gets for a low-car­bon ener­gy sys­tem do not gen­er­al­ly lead to reduced water use. Com­pared to cur­rent con­di­tions, the total vol­ume of water extract­ed and con­sumed world­wide for ther­mal pow­er plants to pro­duce elec­tric­i­ty will tend to con­tin­ue to increase and can only be reduced if the effi­cien­cy of pow­er plant and cool­ing tech­nol­o­gy increas­es. This makes ther­mal elec­tric­i­ty pro­duc­tion increas­ing­ly vul­ner­a­ble to water scarci­ty as a con­se­quence of anthro­pogenic cli­mate change.

The project team con­duct­ed a water foot­print analy­sis along the entire ener­gy sup­ply chain, i.e. tak­ing into account local and remote water demand, and thus com­pared the water con­sump­tion per unit of ener­gy gen­er­at­ed for dif­fer­ent ener­gy sys­tems. The analy­sis showed that ener­gy pro­duc­tion based on renew­able raw mate­ri­als, for exam­ple, has a very high water foot­print. Inte­grat­ed sys­tems using waste mate­ri­als (in this case sug­ar cane bagasse) to gen­er­ate ener­gy can sig­nif­i­cant­ly reduce the water foot­print. Risk and sus­tain­abil­i­ty analy­ses show that ener­gy sup­ply is becom­ing more vul­ner­a­ble with increas­ing­ly fre­quent water scarci­ty and drought under cli­mate change con­di­tions. Espe­cial­ly in arid regions, water is already a scarce resource and a lim­it­ing fac­tor for eco­nom­ic growth and agri­cul­tur­al pro­duc­tion. There, the health of peo­ple and ecosys­tems, sus­tain­able ener­gy pro­duc­tion and water sup­plies are at risk in a chang­ing envi­ron­ment. As hydropow­er gen­er­a­tion impacts fresh­wa­ter megafau­na, bio­di­ver­si­ty should also be con­sid­ered when assess­ing low-car­bon ener­gy tran­si­tion strategies.

New tools for the practice

To address the iden­ti­fied prob­lems, the WANDEL project team, togeth­er with prac­tice part­ners, devel­oped sev­er­al tech­ni­cal and gov­er­nance tools: a new tool for water man­age­ment and a sim­u­la­tor for train­ing pow­er plant staff. These tools enable opti­mal con­trol of dams and impound­ments and increase the effi­cien­cy and safe­ty of water­ways and impound­ed water­cours­es. A new approach, Envi­ron­men­tal Sus­tain­abil­i­ty Assess­ment, extends envi­ron­men­tal impact assess­ment and allows the sus­tain­abil­i­ty of anthro­pogenic process­es to be assessed with upstream sup­ply chains. A set of indi­ca­tors for deter­min­ing the vul­ner­a­bil­i­ty of ener­gy sys­tems and water resources sup­ports deci­sion-mak­ers in assess­ing the sus­tain­abil­i­ty of mea­sures tak­en in the con­text of ener­gy and water security.

Final­ly, the WANDEL project fol­lows an open data approach. All data gen­er­at­ed with­in the project will be made avail­able to the pub­lic on the WAN­DEL-Share plat­form. The pro­jec­t’s open data pol­i­cy pro­vides a sol­id basis for robust deci­sion-mak­ing in the con­text of the tran­si­tion to low-car­bon ener­gy systems.